US6673035B1 - Medical injector and medicament loading system for use therewith - Google Patents

Abstract

The present invention discloses a medical injector and medicament loading system for use therewith. The medicament loading system includes cap for a medicament cartridge. The cap has a post for causing movement of the cartridge stopper toward the seal when the cap engages the medicament cartridge to thereby eliminate adhesion between the medicament chamber and the stopper. The medical injector according to the present invention includes the medicament loading system, i.e. a cartridge assembly, a needle free syringe assembly, and a power pack assembly.

Description

CROSS-REFERENCE TO RELATED APPLICATIONS

The benefit of Provisional Application No. 60/160,893 filed on Oct. 22, 1999 is claimed under 35 U.S.C. §119(e).

FIELD OF THE INVENTION

The present invention is directed to a device for delivery of medicament, and in particular to a compact jet injector and loading system used with standard medicament cartridges.

BACKGROUND OF THE INVENTION

A wide variety of needle free injectors are known in the art. Examples of such injectors include those described in U.S. Pat. No. 5,599,302 issued to Lilley et al., U.S. Pat. No. 5,062,830 to Dunlap, and U.S. Pat. No. 4,790,824 to Morrow et al. In general, these and similar injectors administer medication as a fine, high velocity jet delivered under sufficient pressure to enable the jet to pass through the skin.

Although these injectors are quite successful from a technical point-of-view in achieving the desired delivery of medicament, most commercially available needle free injectors have practical limitations. For example, most needle free injectors are bulky in size. In addition to the undesirable size, some needle free injectors require a complex sequence of coupling and uncoupling the injector to a vial containing the medicament. Thus, there is a perception by the user that the injector is difficult to use. Finally, some needle free injectors cannot be used with standard medicament cartridges, i.e. a cylindrical chamber, typically made of glass, having a first end with a seal penetrable by a needle to draw medicament out of the cartridge and a second end with a movable stopper.

Thus, there exists a need for an improved medical injector and loading system that is compact, usable with standard medicament cartridges, and perceived as easy to operate.

SUMMARY OF INVENTION

The present invention is directed to a cap for a medicament cartridge. The cartridge has a chamber containing medicament, a first end of the chamber having a seal, and a second end of the chamber having a stopper movable towards the seal as medicament is drawn out of the chamber. The cap according to the present invention comprises an interior portion for receiving the second end of the chamber and a post for causing movement of the stopper toward the seal when the cap engages the medicament cartridge to thereby eliminate adhesion between the chamber and the stopper.

The adhesion-eliminating cap can be used in combination with an adapter for transfer of medicament out of the cartridge. The action of the cap in conjunction with the adapter is to allow the purging of gas or air from the cartridge and thus assist in better dosage accuracy and injection quality. The adapter has a first side that mates with the first end of the chamber and has a needle for penetrating the seal upon insertion of the cartridge assembly in the adapter, a second side, and a wall between the first and second sides. The wall has an opening in fluid communication with the needle to create a pathway for medicament as medicament is drawn out of the chamber. Preferably, the first side of the adapter has a plurality of resilient tabs that flex outward upon insertion of the medicament cartridge into the adapter and flex inward after the seal is substantially flush with the wall for locking the medicament cartridge into the adapter.

In one embodiment, the cap and adapter are coupled with a housing. The housing has a first end connectable with the cap and a second end connectable with the adapter. The housing can include a window for visualization of at least a portion of the medicament cartridge.

The cap according to the present invention can be used with a wide variety of injection devices, including a needle free injector. Preferably, the needle free injector comprises a needle free syringe assembly and a power pack assembly. The needle free syringe assembly includes a nozzle member defining a fluid chamber and having a proximal end that mates with the second side of the adapter. The needle free syringe assembly also includes a plunger movable in the fluid chamber. The power pack assembly includes a housing having a proximal end connectable with the distal end of the nozzle member, a trigger assembly, and an energy source operatively associated with the trigger assembly. Movement of the trigger assembly activates the energy source to move the plunger in a first direction to expel medicament from the fluid chamber when the adapter is not connected to the needle free syringe assembly and movement of the plunger in a second direction draws medicament out of the cartridge chamber and into the fluid chamber when the adapter is connected to the needle free syringe assembly.

In one embodiment, the first end of the cartridge assembly housing has a female thread and the cap has a collar insertable into the first end of the cartridge housing. The collar is provided with a male thread that mates with the female thread for connection of the housing with the cap.

The present invention can be used with lyophilized medicament. Specifically, the medicament chamber has a first chamber containing a lyophilized medicament, a second chamber containing a reconstituting fluid, a dividing member separating the first and second chambers, and a bypass channel for providing fluid communication between the first and second chambers upon movement of the dividing member. Fluid pressure generated by movement of the stopper causes movement of the dividing member. The attached adapter assembly allows the venting of the gas or air from the first chamber thereby facilitating dividing member movement and fluid flow. This also allows minimizing the air or gas present in the reconstituted fluid prior to injection.

The present invention is also directed to a medical injector assembly comprising a cartridge assembly for holding a medicament cartridge and a syringe assembly. The medicament cartridge has a chamber containing medicament, a first end of the chamber with a seal, and a second end of the chamber with a stopper movable towards the seal as medicament is drawn out of the chamber. The cartridge assembly comprises a cap with an interior for receiving the second end of the chamber and an end having a post causing movement of the stopper toward the seal as the medicament cartridge is inserted in the cap to thereby eliminate adhesion between the chamber and the stopper. The syringe assembly comprises a fluid chamber, a needle, and a plunger. The plunger is movable in the fluid chamber so that movement in the first direction expels medicament from the fluid chamber. Movement of the plunger in the second direction draws medicament out of the cartridge chamber into the fluid chamber when the syringe assembly is in fluid communication with the medicament cartridge. In one embodiment describing such fluid communication, the needle on the syringe assembly penetrates the seal on the first end of cartridge chamber. Another embodiment anticipates a receiving member for the syringe needle in the adapter. The seal penetrating needle in this embodiment is integral to a first side of the adapter (the side that mates with the first end of the cartridge chamber). The second side of the adapter consists of a receiving member for the syringe and syringe needle designed as to allow fluid communication with the first side of the adapter.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a cross-sectional view of a medical injector and medicament loading system (cartridge assembly) according to the present invention;

FIG. 2 is cross-sectional view of the cartridge assembly of FIG. 1 showing a cap, adapter, and a cartridge housing;

FIG. 3 is a perspective view of an adapter;

FIG. 4 is a cross-sectional view of the adapter of FIG. 3;

FIG. 5 is a cross-sectional view of a cap;

FIG. 6 is a perspective view of the cap of FIG. 5;

FIG. 7 is a perspective view of a cartridge housing;

FIG. 8 is a cross-sectional view of the medical injector of FIG. 1 showing a power pack assembly and a needle free syringe assembly;

FIG. 9 is a perspective view of a nozzle member;

FIG. 10 is a cross-sectional view of the nozzle member of FIG. 9;

FIG. 11 is a perspective view of a plunger;

FIG. 12 is a perspective view of a proximal housing;

FIG. 13 is a cross-sectional view of the proximal housing of FIG. 12;

FIG. 14 is a perspective view of a distal housing;

FIG. 15 is a cross-sectional view of the distal housing of FIG. 14;

FIG. 16 is a perspective view of a dosage detent;

FIG. 17 is a perspective view of detent cover ring;

FIG. 18 is a perspective view of a button cap;

FIG. 19 is a perspective view of a ram;

FIG. 20 is a cross-sectional view of the ram of FIG. 19;

FIG. 21 is a perspective view of ram retainer;

FIG. 22 is a perspective view of a latch spring;

FIG. 23 is a cross-sectional view of a button;

FIG. 24 is a perspective view of the button of FIG. 23;

FIG. 25 is a perspective view of a latch housing;

FIG. 26 is a cross-sectional view of the latch housing of FIG. 25;

FIG. 27 is a perspective view of another embodiment of a trigger assembly;

FIG. 28 is an exploded perspective view of the trigger assembly of FIG. 27;

FIG. 29 is a cross-sectional view of the trigger assembly of FIG. 27 in the latched position with the energy source and button return spring removed;

FIG. 30 is a cross-sectional view of the trigger assembly of FIG. 27 in the fired position with the energy source and button return spring removed;

FIG. 31 is a cross-sectional view of another embodiment of a cartridge assembly for lyophilized medicament prior to reconstitution;

FIG. 32 is a cross-section view of the cartridge assembly of FIG. 27 after the lyophilized medicament has been reconstituted;

FIG. 33 is a perspective view of another embodiment of a cap according to the present invention; and

FIG. 34 is a cross-sectional view of the cap of FIG. 29 with a needle free syringe assembly.

DESCRIPTION OF THE PREFERRED EMBODIMENTS

As shown in FIG. 1, amedical injector10 according to the present invention comprises a medicament loading system orcartridge assembly12, a needlefree syringe assembly14, and apower pack assembly16. As best seen in FIGS. 1 and 2,cartridge assembly12 includes amedicament cartridge18 for holding medicament, anadapter20 for transferring medicament frommedicament cartridge18 to needlefree assembly14, acap22 for holdingmedicament cartridge18, and acartridge housing24. Because medicament cartridges are commercially sold in a variety of sizes,adapter20,cap22, andcartridge housing24 are designed to be used with differentsized medicament cartridges18.Medicament cartridge18 comes pre-filled with medicament and hasseal26 on one end and astopper28 on the other end, which moves towardsseal26 as medicament is drawn out.

The first step in assemblingcartridge assembly12 is to couplemedicament cartridge18 withadapter20.Adapter20 has afirst side30 configured and dimensioned to mate with the end ofmedicament cartridge18 that hasseal26 and asecond side32 configured and dimensioned to mate with needlefree syringe assembly14.Second side32 can have a barrier with a so-called “zero diameter” hole or slit to minimize the potential for leakage and potential of contamination. As disclosed in U.S. Pat. No. 5,846,233, the disclosure of which is incorporated herein by reference, such a hole or slit only allows passage of fluid when stretched, i.e. when needlefree syringe assembly14 is mated tosecond side32. FIGS. 3 and 4 show that first andsecond sides30,32 are separated by awall34.First side30 includes a cartridge opening member, which is aneedle36 in the embodiment shown, for penetratingseal26 and in fluid communication with achannel38 so that a pathway for medicament to be drawn out ofmedicament cartridge18 and into needlefree syringe assembly14 is formed.Needle36 can be a metallic element, analogous to the needle on a conventional syringe, with a beveled end (single bevel, double bevel, tri-bevel, etc.) to facilitate penetratingseal26. Alternatively,needle36 can be a plastic spike. Ifneedle36 is a plastic spike, preferably it is made using an injection molding process so thatneedle36 is integral to wall34.

First side30 also includes a frangible retaining member such asresilient tabs39 that flex outward upon insertion ofmedicament cartridge18 intoadapter20 and flex back inward afterseal26 is substantially flush withwall34 to lock themedicament cartridge18 intoadapter20. Becausetabs39 must be broken to removemedicament cartridge18,tabs39 help ensure thatadapter20 is disposed of after use and not reused with multiple medicament cartridges.

The next step in assemblingcartridge assembly12 is to attachcap22 tomedicament cartridge18. As shown in FIG. 5,cap22 has an interior40 for receiving the end ofmedicament cartridge18 that hasstopper28. Asmedicament cartridge18 is inserted intointerior40, apost42 slightly pushesstopper28 towardseal26. This serves two important functions. First, the slight movement ofstopper28 eliminates any adhesion betweenstopper28 andmedicament cartridge18. Such adhesion occurs becausemedicament cartridge18 is typically made of glass andstopper28 is typically made of silicone rubber and adherence develops during storage ofmedicament cartridge18. Elimination of the adhesion facilitates the drawing of medicament out ofmedicament cartridge18. The slight movement ofstopper28 also purges air frommedicament cartridge18 to minimize introduction of air into needlefree syringe assembly14. As shown in FIG. 2, the movement of thepost42 to purge the air is insufficient to expel a substantial amount of the medicament from thechamber64 with the seal opened by the opening member. In order to achieve the maximum purging effect,adapter20 should be pointing upward whencap22 is attached tomedicament cartridge18. Althoughcap22 is preferably used in conjunction withadapter20 and needlefree assembly14,cap22 can be used with any medicament delivery device that relies on transfer of medicament fromcartridge18 into the device by drawing a vacuum through a needle that has penetratedseal26. As shown in FIG. 2, thepost42 is in a post position with thecap22 andcartridge housing24 engaged, from which position movement of thepost42 past the post position towards theadapter20 and first end of thecartridge18 is prevented.

The final step in assemblingcartridge assembly12 is to connectcap22 tocartridge housing24. As shown in FIGS. 6 and 7,cap22 has acollar44 with amale thread46 and afirst end48 ofcartridge housing24 has afemale thread50.Collar44 inserts intofirst end48 and male andfemale threads46,50 mate so thatcap22 is securely engaged and connected tocartridge housing24 upon twisting, thus engaging thecap22 andcartridge housing24 in an engaged position and association for preventing movement of thecap22 andpost42. As can be seen from the figures, positioning of thecartridge18 in thecap22 with respect to thepost42 and the positioning of the post in the positions of FIG. 1 causes thepost42 to move thestopper28 to release adhesion therebetween. The exterior ofcap22 hasflats52 to facilitate handling. When assembled, awindow54 located oncartridge housing24 provides a visual assurance of proper installation ofmedicament cartridge18, the amount of medicament, and the location ofstopper28. As described in more detail below, markings56 ensure alignment withpower pack assembly16 andridges58 mate with corresponding grooves onpower pack assembly16 to snapcartridge assembly12 ontopower pack assembly16.

Prior to connectingcartridge assembly12 andpower pack assembly16, needlefree syringe assembly14 must be attached topower pack assembly16. FIGS.1 and8-11 show that needlefree syringe assembly14 includes anozzle member60 and aplunger62.Nozzle member60 includes acylindrical fluid chamber64 terminating at one end in acone66 and at the other end in an expandedarea tail68.Cone66 can be a convex cone (as shown), a right circular cone, or any other suitable configuration.Cone66 leads to anorifice69 of a suitable diameter that would produce a jet stream of medicament under a given desired pressure range and depth of injection.Plunger62 has apressure wall70 contoured tocone66 and is positioned to slide withinfluid chamber64.Plunger62 also includes a series ofridges72 formed around its outer periphery to provide a seal and create a sterile boundary between the medicament and the outside of thenozzle member60. As described in more detail below,legs74 ofplunger62 compress around aram76 to operatively coupleplunger62 to ram76.Legs74 are resilient and ordinarily biased outward. However, the relative size offluid chamber64 keepslegs74 compressed inward againstram76 to maintain the coupling. When needlefree syringe assembly14 is removed frompower pack assembly16,legs74 expand out into the expanded area oftail68 so thatplunger62 remains withnozzle member60. Thus, all of needlefree assembly14 can be disposed of after the prescribed number of injections.

Aproximal end78 ofnozzle member60 has a taper that matches that of adaptersecond side32 so that whenproximal end78 is inserted into adaptersecond side32,fluid chamber64 is in fluid communication withneedle36 andchannel38 to allow transfer of medicament frommedicament cartridge18 intofluid chamber64. Adistal end80 ofnozzle member60 has lockingtabs82 and each lockingtab82 is provided with arecess84. Lockingtabs82 andrecess84 mate with corresponding features onpower pack assembly16 to lock needlefree syringe assembly12 topower pack assembly16. These and other structural features ofpower pack assembly16 will now be described.

Power pack assembly16 has a two part housing that includes a proximal housing86 (FIGS. 12 and 13) and a distal housing88 (FIGS.14 and15).Proximal housing86 is a tube having a lumen. A portion of the lumen has a keyedsurface90 configured and dimensioned to receivenozzle member60 of needlefree syringe assembly16. Keyed surface terminates in aledge92. In order to couplenozzle member60 intoproximal housing86,nozzle member60 is inserted intoproximal housing86 and twisted a quarter turn so that lockingtabs82 are resting againstledge92. A resilient biasingmember94, havingprotrusions95 that fit intorecesses84 of lockingtabs82, keepsnozzle member60 biased againstledge92.

The outer surface ofproximal housing86 is provided withcut outs96, which are mirror images of markings56 oncartridge housing24 to ensure proper alignment ofcartridge assembly12 andpower pack assembly16. Cutouts96 also function to allow viewing of medicament once it has been drawn into needlefree syringe assembly14. The outer surface ofproximal housing86 is also provided withthreads98 and the inner surface ofdistal housing88 is provided withthreads100 so that whenproximal housing86 is inserted indistal housing88,threads98 mate withthreads100. As described in more detail below, the relative motion between proximal anddistal housings86,88 allow arming and dosing ofmedical injector10.

Indicia102 on exterior ofproximal housing86 are for determining the dose of medicament to be injected andgrooves104 provide tactile and audible feedback of dosage of medicament. Specifically, only one of the numbers ofindicia102 is viewable throughdosing window106 located ondistal housing88. Asdistal housing88 is rotated counter-clockwise relative toproximal housing86, the number viewable indosing window106 increases to reflect a higher dose. A proximal end ofdistal housing88 hasprotuberances108 for receivingslots110 of a dosing detent112 (FIG.16).Dosing detent112 has a plurality of resilient detent forms114. Whendistal housing88 is slid overproximal housing86, detent forms114 are located overgrooves104 ofproximal housing86. Asdistal housing88 is rotated relative toproximal housing86, detent forms114 flex intogrooves104 to create a physical stop at each unit of dosing. Asdosing detent112 would be visible and potentially subject to damage whencartridge assembly12 is not connected to power pack assembly14 (as viewed from the end), adetent cover ring116 protectsdosing detent112. As shown in FIG. 17,detent cover ring116 haspegs118. Thesepegs118 fit into thoseslots110 ofdosing detent112 that are not used forprotuberances108.

A distal end ofdistal housing88 hascrush ribs120 for providing an interference fit with a button cap122 (FIG.18). Aslot124 in aclip126 ofbutton cap122 slides intoridge128 ofdistal housing88. Clip126 functions like a pen clip and provides a convenient way to attachinjector10 to an article of clothing, a clipboard, etc.Clip126 can also be used for leverage when rotatingdistal housing88 with respect toproximal housing86 for arming and dosing.

As previously noted,plunger62 is connected to ram76. This connection forms when needlefree syringe assembly14 is coupled topower pack assembly16. Specifically, asnozzle member60 is inserted inproximal housing86, aproximal end130 of ram76 (FIGS. 19 and 20) pushes againstplunger62 to moveplunger62 out of the expanded area oftail68 so thatlegs74 compress aroundring132 to connectplunger62 to ram76.Ram76 is in turn operatively associated with anenergy source134 for movingram76 andplunger62 to force medicament out oforifice69 ofnozzle member60.Energy source134 can be a coil spring, a gas spring, or a gas propellant.Ram76 has acentral body136 that terminates in adisk138.Disk138 cooperates with aram retainer140, shown in FIGS. 1 and 21, to limit the distance that ram76 can travel towardnozzle member60. One important safety aspect of this feature is thatram76 cannot become a dangerous projectile ifinjector assembly10 is fired when needlefree syringe assembly14 is not present.

Medical injector10 includes a trigger assembly for firingpower pack assembly16. Two exemplary embodiments of a trigger assembly are now described. In the first, the trigger assembly includes a latch spring142 (FIG. 22) for holdingenergy source134 until firing, a button144 (FIGS. 23 and 24) for firingmedical injector10, a button return spring146 (FIGS. 1 and 8) for biasingbutton144 outward, a latch housing148 (FIGS.25 and26) which cooperates withlatch spring142 andbutton144 to allowram76 to move upon firing, and button cap122 (FIG. 18) for holding the trigger assembly in place. The distal end ofram76 has acavity150 for receivinglatch spring142.Cavity150 has a pair ofnotches152 out of which U-shaped ends154 oflatch spring142 can protrude whenlatch spring142 is not compressed. Aftermedical injector10 is fired, ram76 has traveled proximally throughdistal housing88 so thatcavity150 is positioned within abore156 oflatch housing148. Because of the size ofbore156 compared to latchspring142,latch spring142 is compressed so that all oflatch spring142 is contained incavity150 whenlatch spring142 is withinbore156. In other words, U-shaped ends154 do not protrude throughnotches152 whenlatch spring142 is withinbore156. In order to re-armmedical injector10,distal housing88 is rotated clockwise with respect toproximal housing86. This rotation compressesenergy source134 between aridge158 oflatch housing148 anddisk138 ofram76. Asdistal housing88 moves proximally towardproximal housing86, latchhousing148 also moves proximally untilcavity150 ofram76 is located within an expandedkeyed area160. Whennotches152 ofcavity150 reach keyedarea160, U-shaped ends154 oflatch spring142 expand to retainlatch spring142 to keyedarea160 and thereby keepenergy source134 compressed. In order to releaselatch spring142 from keyedarea160,button144 must be depressed.Depressing button144 causes rampedsurfaces162 to move proximally and thereby compresslatch spring142 to disengage U-shaped ends154 from keyedarea160.

FIGS. 27-30 show the second exemplary embodiment of a trigger assembly. When the components are assembled, the position oflatch housing148 is fixed,energy source134 is trying to pushram76 away fromlatch housing148, andbutton return spring146 is trying to pushbutton144 fromlatch housing148. Whenram76 compressesenergy source134, aninternal groove164 of increased diameter ofram76 lines up withlatch balls166 andholes168 inlatch housing148. This allowsbutton return spring146 to movebutton144 away from latch housing which forces latchballs166 intointernal groove164 ofram76. This movement is possible because astem170 ofbutton144 has a taperingsurface172 leading to anarea174 of decreased diameter (in comparison to the rest of stem170).Latch balls166 are now captured inlatch housing148 and holdram76 in place. This is referred to as the latched position and is best seen in FIG.29.

Whenbutton144 is depressed,area174 onstem170 ofbutton144 lines up withholes168 inlatch housing148. This allowsenergy source134 to forceram76 away fromlatch housing148, thereby pushinglatch balls166 intoarea174 onstem170. This is referred to as the fired position and is best seen in FIG.30. As is evident from FIGS. 29 and 30,latch balls166 are always contained betweenram76, latchhousing148, andbutton144. This arrangement minimizes the possibility that latchballs166 become dislodged and increases the reliability of the trigger assembly.

The operation ofmedical injector10 will now be described, with a just-fired injector as the starting point and with reference to the first-described trigger assembly. In order to re-arminjector10, the user rotatesdistal housing88 clockwise with respect toproximal housing86 to compressenergy source134 betweenridge158 oflatch housing148 anddisk138 ofram76. The rotation continues untillatch spring142 is retained within keyedarea160 to thereby keepenergy source134 compressed. Medicament is drawn intofluid chamber64 by counterclockwise rotation ofdistal housing88 with respect toproximal housing86, thus aspirating the fluid. Specifically, the rotation causes distal movement ofram76 and plunger62 (becauseram76 is locked to distal housing88), which in turn creates a vacuum influid chamber64 to draw medicament throughmedicament cartridge18 andadapter20 and intofluid chamber64. In order to fireinjector10,cartridge assembly12 is removed from needlefree assembly14 and the proximal end of needlefree syringe assembly14 is placed against the skin at the desired injection site.Button144 is depressed to disengagelatch spring142 from keyedarea160. This allowsenergy source134 to return to its uncompressed state and moveram76 andplunger62 proximally so that medicament is ejected throughorifice69 at a pressure sufficient to jet inject the medicament.

As is evident from the description of the structure and operation ofmedical injector10,injector10 is a compact injector that is convenient to transport.Injector10 is also simple to use and operate. In particular,injector10 is ready to be loaded everytime cartridge assembly12 is placed on needlefree syringe assembly14.

The three assembly (cartridge, needle free syringe, and power pack) design allows an individual assembly to be modified without affected the other two assemblies. For example, FIGS. 31 and 32 show another embodiment of acartridge assembly200 that is used for lyophilized medicaments that are reconstituted just prior to use. Alyophilized medicament cartridge202 has afirst chamber204 that contains the lyophilized medicament, asecond chamber206 that contains the reconstituting fluid, and a dividingstopper208 separating the two.Medicament cartridge202 also has abypass210 so that once dividingstopper208 reaches bypass210, the reconstituting fluid can enterfirst chamber204 to reconstitute the lyophilized medicament. Movement of dividing stopper results from the threading ofcap22 tocartridge housing24, withthreads46,50. Specifically, ascap22 is threaded ontocartridge housing24, post42 pushesstopper28 towardsadapter20. The resulting fluid pressure of reconstituting fluidcauses dividing stopper208 to also move towardadapter20 untilbypass210 is reached. Once dividingstopper208 reaches bypass210, further movement ofstopper28 allows the reconstituting fluid to enter intofirst chamber204 and reconstitute the lyophilized medicament.

FIG. 33 shows another embodiment of acap212 with abore214 having a shape and size that matches that of the proximal end ofnozzle member60 of needlefree syringe assembly14. As shown in FIG. 34, the proximal end ofnozzle member60 fits snugly intobore214. Because of the tight fit,cap212 andnozzle member60 rotate together. Thus,cap212 can be used to attach or detachnozzle member60 from needlefree syringe assembly14.

While it is apparent that the illustrative embodiments of the invention herein disclosed fulfil the objectives stated above, it will be appreciated that numerous modifications and other embodiments may be devised by those skilled in the art. Therefore, it will be understood that the appended claims are intended to cover all such modifications and embodiments which come within the spirit and scope of the present invention.

Claims (25)

What is claimed is:

1. A medical injector assembly, comprising:

a syringe assembly comprising:

a nozzle member defining a fluid chamber and having a proximal end configured and dimensioned for mating with the second side of the adapter and a distal end; and

a plunger movable in the fluid chamber;

a power pack assembly comprising:

a housing having a proximal end connectable with the distal end of the nozzle member and a distal end;

a trigger assembly comprising:

a ram having proximal and distal ends and a bore, the proximal end coupled to the plunger and the bore having a cavity,

a latch housing having a tubular body with a channel, at least a portion of the body insertable in the bore of the ram,

a plurality of latch holes located on the body of the latch housing, each of the plurality of latch holes having associated therewith a latch ball, and

a button having a stem with proximal and distal ends and a groove located near the distal end, at least a portion of the stem is insertable in the channel of the latch housing,

wherein in a latched position each latch ball is captured in the cavity of the ram bore to thereby prevent the energy source from moving the plunger in the first direction and in a fired position the groove of the button stem aligns with the plurality of latch holes and latch balls to release the latch balls from the cavity of the ram bore and thereby activate the energy source to move the plunger in the first direction; and

an energy source operatively associated with the trigger assembly so that movement of the trigger assembly activates the energy source to move the plunger in a first direction to expel medicament from the fluid chamber.

2. The medical injector ofclaim 1, further comprising:

a cartridge assembly for holding a medicament cartridge with a chamber containing medicament, a first end of the chamber having a seal, and a second end of the chamber having a stopper movable towards the seal as medicament is drawn out of the chamber, the cartridge assembly comprising:

an adapter with a first side configured and dimensioned to mate with the first end of the chamber and having a needle for penetrating the seal upon insertion of the cartridge assembly in the adapter, a second side, and a wall therebetween, the wall having an opening in fluid communication with the needle to create a pathway for medicament as medicament is drawn out of the chamber,

a cap and cartridge housing with an interior for receiving the second end of the chamber and an end having a post causing movement of the stopper toward the seal as the medicament cartridge is inserted in the interior to thereby eliminate adhesion between the chamber and the stopper, and

a housing having a first end connectable with the cap and a second end connectable with the adapter.

3. The medical injector ofclaim 2, wherein the energy source and the trigger are associated to move the plunger in the first direction to expel the medicament from the fluid chamber when the cartridge assembly is not connected to the syringe assembly.

4. The medical injector ofclaim 3, wherein movement of the plunger in a second direction draws medicament out of the cartridge chamber and into the fluid chamber when the cartridge assembly is connected to the syringe assembly.

5. The medical injector ofclaim 1, wherein the syringe assembly comprises a needle free syringe assembly.

6. An injecting device, comprising:

the medical injector assembly ofclaim 1; and

a filling assembly that comprises:

a cartridge housing configured for receiving a first end of a cartridge that has a chamber containing a medicament and first and second ends, the first end including a seal for sealing the medicament in the chamber, and the second end including a stopper sealingly disposed in the chamber;

an adapter associated with the cartridge housing and configured for coupling the chamber to the syringe assembly for transferring the medicament to the fluid chamber; and

a post associated with the cartridge housing in a post position from which movement towards the adapter is substantially prevented, wherein the post is configured such that positioning of the second end of the cartridge in a first position with respect to the post and of the post in the post position causes the post to displace the stopper towards the seal by an amount sufficient to reduce or eliminate adhesion between the chamber and the stopper for permitting filling of the fluid chamber from the chamber and for substantially preventing said movement of the cartridge past the first position.

7. The injecting device ofclaim 6, wherein the post is configured such that movement to the first position is insufficient to expel a substantial amount of the medicament from the chamber with the seal opened by the opening member.

8. The injecting device ofclaim 6, further comprising a cap having an engaged association with the cartridge housing in an engaged position from which movement therebetween past the engaged position towards the adapter is substantially prevented, wherein the post extends from the cap in the post position and the cap is configured for substantially preventing said movement of the cartridge past the first position.

9. The injecting device ofclaim 8, wherein the cap is configured and dimensioned for receiving the second end of the cartridge such that movement of the second end into the cap causes the post to displace the stopper towards the seal by said amount sufficient to reduce or eliminate adhesion between the chamber and the stopper.

10. The injecting device ofclaim 8, wherein the cap and the adapter housing are configured such that the engagement thereof causes sufficient displacement of the stopper for purging an amount of any air contained in the cartridge with the seal opened prior to the attachment to the syringe assembly.

11. The injecting device ofclaim 6, wherein the post is disposed and configured such that the engagement of the cap with the adapter housing causes the post to move the seal to the first position.

12. The injecting device ofclaim 6, wherein the adapter comprises a cartridge opening member configured for opening the seal to permit extraction of the medicament therefrom.

13. The injecting device ofclaim 12, wherein the adapter comprises a needle disposed and configured for penetrating the seal for said opening of the seal.

14. The injecting device ofclaim 6, wherein the adapter comprises a wall that defines a wall opening in fluid communication with the cartridge opening member to create a pathway for drawing the medicament out of the chamber.

15. The injecting device ofclaim 6, wherein the adapter is configured for connecting the cartridge to the syringe assembly to allow the medicament to flow from the chamber into the fluid chamber.

16. The injecting device ofclaim 6, wherein the adapter is configured for engaging the first end of the cartridge.

17. The injecting device ofclaim 16, wherein the adapter comprises a frangible retaining member configured for engaging and retaining the first end of the cartridge and for breaking upon removal of the cartridge from the adapter housing for inhibiting repeat uses of the filling assembly.

18. The injecting device ofclaim 17, wherein the frangible retaining member comprised a plurality of resilient tabs configured for flexing outward upon insertion of the medicament cartridge into the adapter and flexing inward about the first end of the cartridge to engage and retain the cartridge.

19. The injecting device ofclaim 6, wherein the post is associated with the cartridge housing in the post position for allowing the medicament to be aspirated from the chamber into the fluid chamber.

20. The injecting device ofclaim 6, wherein the housing defines a window for viewing at least a portion of the medicament cartridge.

21. The injecting device ofclaim 6, further comprising the cartridge.

22. The injecting device ofclaim 21, wherein the medicament chamber comprises a first chamber containing a lyophilized medicament, a second chamber containing a reconstituting fluid, a dividing member separating the first and second chambers, and a bypass channel for providing fluid communication between the first and second chambers upon movement of the dividing member, wherein fluid pressure generated by movement of the stopper causes movement of the dividing member.

23. The injecting device ofclaim 1, wherein the syringe assembly and filling assembly comprise threaded portions configured for connecting to each other.

24. A medical injector assembly, comprising:

a needle free syringe assembly comprising:

a nozzle member defining a fluid chamber and having a proximal end configured and dimensioned for mating with the second side of the adapter and a distal end; and

a plunger movable in the fluid chamber; and

a power pack assembly comprising:

a housing having a proximal end connectable with the distal end of the nozzle member and a distal end;

a trigger assembly comprising:

a ram having a proximal end coupled to the plunger and a distal end with a cavity,

a latch housing connected to the power pack assembly and having a body with a bore leading to a keyed opening, the bore and keyed opening configured and dimensioned for receiving at least a portion of the ram, and

a latch spring located in the ram cavity and having first and second U-shaped ends, wherein the U-shaped ends extend through cutouts located in the ram when the latch spring is located in the keyed opening to thereby prevent the energy source from moving the plunger in the first direction and the U-shaped ends compress within the ram cavity when the latch spring is located in the bore to thereby allow the energy source to move the plunger in the first direction; and

an energy source operatively associated with the trigger assembly so that movement of the trigger assembly activates the energy source to move the plunger in a first direction to expel medicament from the fluid chamber when the cartridge assembly is not connected to the needle free syringe assembly and movement of the plunger in a second direction draws medicament out of the cartridge chamber and into the fluid chamber when the cartridge assembly is connected to the needle free syringe assembly.

25. The medical injector assembly ofclaim 24, further comprising a cartridge assembly for holding a medicament cartridge with a chamber containing medicament, a first end of the chamber having a seal, and a second end of the chamber having a stopper movable towards the seal as medicament is drawn out of the chamber, the cartridge assembly comprising:

an adapter with a first side configured and dimensioned to mate with the first end of the chamber and having a needle for penetrating the seal upon insertion of the cartridge assembly in the adapter, a second side, and a wall therebetween, the wall having an opening in fluid communication with the needle to create a pathway for medicament as medicament is drawn out of the chamber;

a cap with an interior for receiving the second end of the chamber and an end having a post causing movement of the stopper toward the seal as the medicament cartridge is inserted in the cap to thereby eliminate adhesion between the chamber and the stopper; and

a housing having a first end connectable with the cap and a second end connectable with the adapter.

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